Variable speed transmission device



April 7, 1942.. F. L. FULLER VARIABLE SPEED TRANSMISSION DEVICE Filed Nov. 5, 1940 3 Sheets-Sheet l IP EQ I ATTO RN EY April 7, 1942. F. L. FULLER I VARIABLE SPEED TRANSMISSION DEVICE Filed Nov. 5, 1940 -5 Sheets-Sheet 2 mmml IHI IHHHHHHIIIIIII M INVENTQR 405,44

ATTORNEY April 7, 1942. F. L. FULLER 2,278,983

VARIABLE SPEED TRANSMISSION DEVICE 7 Filed NOV. '5, 1940 5 SheetsSheet 3 ATTORNEY Q Patented Apr. 7, 1942 VARIABLE SPEED TRANSMISSION DEVICE Frederick L. Fuller, West Orange, N. J., assignor to International Business Machines Corporation, New York, N. Y., a corporation of New York Application November 5, 1940, Serial No. 364,386

5 Claims. (Cl

This invention relates to variable speed transmission devices, and particularly to such devices whereby variable transmission speeds are obtained by employing intermediate driving means which are capable of being actuated in two directions simultaneously.

An object of the present invention resides in the provision of gearing means interposed between the driving and driven members, which gearing means have different movements imparted'thereto simultaneously, for controlling variably the movement of the driven means.

To this end, spiral gearing means are provided which are carried by an axially movable shaft, so that the said gearing means can be rotated at variable speeds, and also be displaced axially,-

at the same time, for controlling the operation of the .driven member. Suitable control means, such as a cam and follower arm, are provided for actuating the spiral gearing means axially, which control means are under the control of, or rotated by, the driving member.

Another object of the invention resides in the provision of spiral gearing means, the operation of which is controlled by the driving member, for controlling the variable operation of the driven member in accordance with the speed of rotation and degree of axial movement thereof.

Another object of the invention resides in the provision of means, under control of the driving means for controlling the degree of axial movement imparted to the said spiral gearing means.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawings:

Fig. l is a front elevation view of the device.

Fig. 2 is a side view, partially in section of the device shown in Fig l.

Fig. 3 is a front elevation view, partially in section, of a modification of the device.

Fig. 4 is a sectional view along lines 4-4 of Fig. 3.

Fig. 5 is a sectional view along lines 5-5 of Fig. 3.

' Referring now to Figs. 1 and 2, the device is shown to comprisespiral gearing means inter-- pcsed between the driving member and driven member, said means consisting of the spiral gears l and H. The said gears are fixed to each other, and preferably are formed integrally as shown, and in turn are mounted rotatably on .74-393) the shaft I2. The said shaft is adapted to be positioned axially by the cam follower arm I3 which ispivotally mounted on a side frame l4. Guide members l5-and l6 for the movable shaft l2 are provided and are affixed to the side frame I l. The free end of the follower arm I3 is bifurcated and fitted into a slot ll formed in the shaft l2, to engage the stud member l8 which is fixedly positioned in the slot. The stud member can be formed as an integral part of the shaft l2, or can be an insertable member which is suitably fixed or pinned to the shaft.

The driving member comprises the shaft l9 loosely mounted in the side frames it and lea, and the gear 20 which is secured to the said shaft, and in mesh with an intermediate gear 2| secured to shaft 22, the latter also being.

loosely mounted in the said side frames. The shaft I9 has affixed thereto a set of complementary earns 23 and 2t which cooperate with the rollers 25 and 26 respectively, carried by the pivoted follower arm l3.

In view of the description up to this point, it is seen that, upon rotation of the shaft l9, by any suitable means, the said cams 23 and 24 are rotated to position or oscillate the cam follower arm l3 about its pivot, so that in turn the shaft I2, carrying the spiral gears ill and II is positioned axially or reciprocated. It is evident that the degree of axial movement of the said shaft is dependent upon the configurations of the cams.23 and 24, and it is obvious that the degree of axial movement can be adjusted or selected to any desired extent by varying the said cam configurations accordingly.

In this manner onetype of movement is imparted to the spiral gears Ill and H. Another and different type of movement is imparted to the said gears by means of the gear 21 which is secured to the shaft 22, and the described gearing designated by the reference characters 20 and 2|. Upon rotation of shaft l9 and gear 20,

shaft 22 and gear 21 are rotated to effect rotation of spiral gears l0 and i l. Meshing with the said gear H is gear 28, the latter being secured to the driven member, namely shaft 29, which is suitably journaled in the side frames l4 and Ma. Thus, it is seen that'the driven shaft 29 is rotated directly by the spiral gear i I.

In practice, the device described has been found to permit greater variations in the speeds of rotation of the driven shaft in shorter timed intervals than the prior art devices. For example, in statistical machines where space limitations are an important factor, it is necessary to effect a number of speed variations in succession in very brief timed intervals. It has been found that the present invention affords numerous advantages over the known devices of this type;

in certain cases the successive speed ratios vary as much as 350% which must be efiectedin th fractions of a second. In this connection, it

should be mentioned that shaft I9 is'rotated at a constant speed, at all times, and from the description set forth, it is understood that shaft 22 is rotated at a constant speed, and that spiral gears in and II and shaft 29 are rotated at different speeds depending upon the axial displacement of shaft 2. For example, at the times, during th rotation of shaft I9 and cams 23 and 'It .is evident that the decreased and increased speeds of rotation are dependent upon the rate of axial movement imparted to shaft l2, which in turn is under control of the said cams 23 and 24.

meshes with said gear 31, and gear 33 meshes with gear 4| which is secured to the output shaft 3|.

The axial movement of gears 38 and 33 is controlled. by a cam follower 42 which is fixed to a sleeve member 43a, the latter being secured to or formed as an integral part of the spiral gearing'means. :The said cam follower 42 is provided with a suitable extension member 43 adaptedto cooperate with the groove 44 formed in the cam member 34. A suitable-support and guide collar 45 for the cam follower is loosely mounted on shaft 3|. It is seen that the said follower 42 is shaped so that thearcuate extensions 46 partially surround the dwelled section I of collar 45.

The operation of the described modification is as'follows: Upon rotation of gears 32, 33 and shaft 30, gear 31 is set in motion bymeans of gear and shaft 36; The spiral gears 33 and 39 are driven by gear 31 to drive gear 4| and shaft 3|. Cam member 34 is also rotated by shaft 30 to displac the cam follower 42 and spiral gears 38 and 39 axiall in accordance with the configuration of cam groove 44. The axial movement of the spiral gearing means controls the variations in the speed of rotation of gear It is understood now, that that the spiral gearing means, namely gears I0 and II, are actuated in two directions simultaneously, and in addition thereto, are. actuated at varying rates Y in each of the two directions simultaneously. The varying rate of axial displacement of shaft l2 depends, upon the configurations of the cams 23 and 24, and the varying rate of rotation of gears I 0 and II depends upon the rate and direction of movement of th shaft". Without the use of spiral gearing means interposed between the driving and driven members, as described, the varying speeds of rotation of gears I0 and I I could not be obtained, and consequently the greater and more abrupt changes in speed transmission afforded by the described device could not be effected inthe short timed interval scribed as the driven member can'be used as the driving shaft, and shaft is then becomes the driven member. Under these conditions, obviously the changes in speed transmissions are in a reverse sequence as compared to the changes in speed transmissions when shaft I 9 is employed as the driving member.

Referring now to Figs. 3, 4, and 5, a modification of the described device is shown. In this embodiment of the different shafts carrying the various control elements ar arranged in a parallel relationship. 'Ihedriving and driven members or shafts ar indicated by the reference characters 30 and 3|, respectively. Secured at one end of the shaft 30 are the gears 32 and 33, and secured to the other end of the said shaft is the cam member 34. Gear 32 can be rotated by any suitable cooperating driving means. Gear 33 meshes with gear 33, the latter being pinned to 4| and shaft 3| precisely as described hereinabove. i

Due to the great variations in rotative speeds of the output shaft 3| in very brief intervals which are effected by the described device, a suitable braking mechanism can be provided to operate on -the output shaft, and thereby assist in the regulation of the rotative speeds of this shaft. Excessive wear of the cooperating parts can be reduced by employing such a brake mechanism due to the inertia of the moving parts, particularly when the device is operated at excessive speeds, and abnormal and abrupt changes in rotative speeds are eifected.

The operation of the brake mechanism, at such timed intervals, when it is desired to decrease abruptly the rotative speed of shaft 3|, is controlled by cam element 41. A roller 43, rotatably supported by a spring urged follower arm 49, is adapted to cooperatewith the said cam element. The follower arm is pivotally supported by arm 50- which in turn is loowly connected to the ends of arcuately shaped arms II and 32 which normally are urged to a contracted condition by means of spring 33. The arms II and 52 are pivotally mounted on shaft '43, and as shown each arm carries aloosely supported shoe 54, which shoes are arranged to engage a hub II carried on one end of the shaft 3|. The arms II and 52 are shown to be expanded by virtue of the action of arm 50 thereupon, which arm is urged to the right as viewed in Fig. 5, due to the engagemen'tbf the raised portion of cam element 41 with the roller 48 carried by arm'll. The configuration of the cam element is designed so that the action of the cam and controlled brake -mechanism is effected in synchronism with the shaft 36 which carries gear 31. The spiral gearing means in this modification comprises the spiral gears 33 and 33 which are integrally formed, and are keyed to shaft 40 for rotation therewith. The said shafts 30, 3|, 36, and 40 ar suitably journaled in side frames which are shown in dotted outline. The spiral gear 33 action of cam 34 and the controlled spiral gearing means, that is, when the spiral gearing means is positioned axially at such a rate so as to effect an abrupt decrease in the'speed of rotation-of shaft 3|, the configuration of the cam element is such that the lower portions of the cam element engage the roller 43 and permit the brake leased, which release is effected at such times when it is desired to accelerate the speed of rotation of shaft 3|.

While there has been shown and described and pointed out the fundamental novel features of the invention as applied to a single modification.

it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art, Without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. A variable speed transmission device comprising a rotatable driving member and a driven member, an axially displaceable shaft, spiral gearing means, rotatably mounted on said shaft, actuated by the driving member, upon rotation thereof, for controlling the operation of said driven member, a cam element actuated by the said driving member, and-ream follower means controlled by said cam element for controlling the axial displacement of said shaft and spiral gearing means, thereby controlling the rate of operation of the said driven member.

2. A variable speed transmission device comprising a rotatable driving member and a driven member, axially displaceable spiral gearing means comprising a pair of directly coupled spiral gears, one of said spiral gears being actuated by the driving member upon rotation thereof, the other spiral gear being efiective to operate the said driven member, a cam element actuated by the said driving member, and means controlled by said cam element for controlling the axial displacement of said spiral gearing means, thereby controlling the rate of operation of the said driven member.

3. A variable speed transmission device comprising a rotatable driving member and a driven member, axially displaceable spiral gearing means comprising a pair of directly coupled spiral gears, one of said spiral gears being actuated by the driving member, upon rotation thereof, the other spiral gear being efiective to operate the said driven member, means actuated by one of said members, and means controlled by the said last mentioned means for controlling the axial displacement of said spiral gearing means, thereby controlling the rate of operation of the said driven member.

4. A variable speed transmission device comprising a rotatable driving member and a driven member, gearing elements comprising a pair of directly coupled spiral gears, one of said spiral gears being actuated by the driving member, upon rotation thereof, the other spiral gear being effective to operate the said driven member, and means under control of one of said members for imparting to said gearing elements different movements simultaneously, at varying rates, thereby controlling, at variable rates, the operation of said driven member.

5. A variable speed transmission comprising a rotatable driving member and a driven member, gearing elements actuated by the driving member, upon rotation thereof, for controlling the operation of said driven member, means under control of one 'of said members for imparting to said gearing elements different movements simultaneously, at varying rates, thereby controlling, at

variable rates, the operation of said driven member, braking mechanism cooperating with said driven member, and means operating in synchronism with said imparting means for controlling the operations of said braking mechanism when the driven member is operated at predetermined rates.

FREDERICK L. FULLER. 

